1. Field of the Invention
The present invention is a device for people with a physical disability, injury or disease. More specifically, the present invention is directed to a reciprocal gait orthosis device for assisting handicapped people to stand, walk or ambulate.
2. Description of the Related Art
People with physical disabilities of their lower extremities have traditionally used a manual or machine operated wheelchair to provide mobility. However, there are several problems associated with the use of the wheelchair. For example, the wheelchair can only move within buildings and vehicles which are specifically wheelchair-accessible. Moreover, the person is confined to a seat of the wheelchair and is prone to develop leg tightness and pressure sores. If the wheelchair user is a child, the inability to move around with other children may also cause the user to develop low self esteem and become depressed.
In response to these problems associated with the conventional use of wheelchairs, orthotic devices have been developed to assist people to stand, walk and ambulate and thus become more mobile. One common type of orthotic device is a hip-knee-ankle-foot orthosis (HKAFO) device having a trunk section, two leg sections and two lateral hip joints to connect the two legs sections to the trunk section. Locks are typically provided with each of the hip joints and are placed in a unlocked position when the person wearing the HKAFO device intends to sit down.
The locks are placed in a locked position when the person uses a walker or forearm crutch with the HKAFO device for standing and moving with a swing-through or hopping type gait. Although the use of a HKAFO device provides greater mobility of areas not previously accessible with the use of a wheelchair, the person using the HKAFO device must move both legs together along a single plane. The HKAFO device is also heavy and cumbersome. Thus, the person using the HKAFO device must expend much of their energy to move both legs together in a swing-through or swivel gait pattern. Moreover, for those individuals with some strength in their lower extremities, the need to lock the hip joint for using the HKAFO device inhibits the gradual rehabilitation of these extremities.
The reciprocating gait orthosis (RGO) device is a type of orthotic device designed to overcome the aforementioned problems associated with HKAFO devices. A typical RGO device comprises a dual-cable system connected to leg supports so as to alternatively transfer energy in the movement of one leg to the other leg. With the dual-cable system, one cable causes flexion of one leg while the other cable causes extension of the other leg in a reciprocal gait manner. One exemplary RGO device is disclosed in U.S. Pat. No. 4,946,156 to Hart.
However, the dual-cable system is heavy and cumbersome to use. RGO devices having this dual-cable system are also more expensive than HKAFO devices. Moreover, the dual-cable system is not configured for enabling ambulation of people having hip joint contracture or tightness or significant knee flexion contracture, for example, of more than 15 degrees of joint contracture. Thus, people having such contractures would have to ambulate with the hip and knee joints locked with a swing-through or swivel-gait pattern as with the HKAFO device. The required energy for such swing-through or swivel gait ambulation is significant and limits the rehabilitation of individuals having some strength in their hip and lower leg and decreased mobility in other ranges.
Therefore, people having significant hip or knee contractures must first use a HKAFO device while undergoing intensive stretching, joint mobilization and possibly surgery to reduce such contractures. Once the contracture is decreased, the person is now fitted with a RGO device and continues rehabilitation using the RGO device. However, gradual rehabilitation using HKAFO and RGO devices often cannot reduce hip and knee contractures. In this case, the user cannot use a conventional RGO device to perform reciprocal ambulation. There is thus a need in the art for a novel RGO device that is lightweight and is suitable for people having various degrees of contractures at the hip and knee joint.
The present invention is directed to a reciprocal gait apparatus for use as an orthotic or prosthetic. In one embodiment, the apparatus comprises a torso vest securable about the torso of a patient, a leg support securable on a leg of a patient and a hip joint coupled to and disposed between the torso vest and leg support, and two resilient members respectively disposed substantially anterior and posterior about the hip joint and coupled to the torso vest and leg support. A first resilient member flexes the leg support in a forward direction in response to lifting of said leg support. A second resilient member moves the leg support in a backward direction once the leg support has been substantially flexed in the forward direction along a range of motion for said leg support. Another embodiment of the reciprocal gait apparatus comprise a gear assembly and two belts for implementing reciprocal gait.